Definition of Patient

Patient: A person under health care. The person may be waiting for this care or may be receiving it or may have already received it. There is considerable lack of agreement about the precise meaning of the term "patient."

It is diversely defined as, for examples:

• A person who requires medical care.
• A person receiving medical or dental care or treatment.
• A person under a physician's care for a particular disease or condition.
• A person who is waiting for or undergoing medical treatment and care
• An individual who is receiving needed professional services that are directed by a licensed practitioner of the healing arts toward maintenance, improvement or protection of health or lessening of illness, disability or pain. (US Centers for Medicare & Medicaid Services)
• A sick, injured or wounded soldier who receives medical care or treatment from medically trained personnel. (US Army Medical Command)

From the Latin verb "patior" meaning "to suffer" both in the sense of feeling pain and in the sense of forbearance. Thus, the two uses of the word "patient" -- as a noun denoting "someone who suffers" and as an adjective meaning "to bear with forbearance" -- stem from the same origin.